The Virtuoso design environment is used for analog design and can be used in conjunction with Spice simulators from Cadence or third parties. However, Cadence specifically provides an integration product called Oasis that customers are required to license for that purpose.

In a complaint filed last week in U.S. District Court in Northern California, Cadence alleges BDA uses an alternative interface to allow customers to link its Analog FastSpice (AFS) Spice simulator to Cadence Virtuoso ADE without obtaining an Oasis license. Cadence claims this is in breach of a cooperation contract that it has with Berkeley Design Automation and that BDA has also violated the Digital Millennium Copyright Act.

Cadence's suit seeks damages for loss of profit, loss of licensing fees. It also asks the court to stop BDA from integrating AFS without going through Oasis.

A spokesperson for Cadence said that prior to filing the lawsuit the company tried repeatedly over many months to work with BDA's management team to rectify the situation. But those efforts failed to persuade BDA, the spokesperson said. Cadence also did not renew BDA's participation in the Cadence Connections partner program as a result, the spokesperson said.

"The ability of companies to protect their intellectual property is foundational to the industry," Cadence said through an official statement. "Cadence is committed to interoperability with its business partners in order to provide value to customers, and regrets that it has been left with no other choice than to file this complaint. Cadence remains fully prepared to support our common customers via an authorized integration to BDA’s products through a licensed Oasis interface."

BDA did not immediately respond to a request for comment on the lawsuit.